The present invention relates to a metal gasket, and more particularly relates to an improvement of a composite metal gasket advantageously used for sealing of internal engines.
One conventional metal gasket of such a type is disclosed in Japanese Utility Model Opening Sho.59-152249. This metal gasket has a composite structure in which a substrate made of hard metal is covered with covering layers which are made of soft metal and clad to both surfaces of the substrate. During production of such a composite metal gasket, plastic deformation such as cladding and stamping causes hardening of the covering layers and, as a consequence, it is very difficult to obtain a uniform soft surface condition on the produced metal gasket. When such a metal gasket is employed in sealing, the metal gasket cannot assure sufficient sealing of the rough surface of the object being tested.